Neuro-muscular Junctions and Muscle Contraction

Neuro-muscular Junctions and Muscle Contraction

Learning Objectives:

• describe the roles of neuromuscular junctions, transverse system tubules and sarcoplasmic reticulum in stimulating contraction in striated muscle;

• describe the ultrastructure of striated muscle with particular reference to sarcomere structure

• explain how a muscle contracts;

• explain how oxygen debt develops and how a muscle may become fatigued.

Sarcolemma

• the plasma membrane of the muscle cell and is surrounded by basement membrane and endomysial connective tissue

• an excitable membrane and shares many properties with the neuronal cell membrane

Sarcoplasmic reticulum

• a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells.

Multiple Select

Which of the following are specialized functional properties of skeletal muscle?

• Irrititability

• Contractility

• Extensibility

• Elasticity

Multiple Choice

The association site of the axon terminal of the motor neuron and sarcolemma of a muscle is called a ...

• synaptic cleft

• neuromuscular junction

• motor end plate

• neurotranmitter

Fill in the Blanks

ion entry causes some synaptic vesicles to release acetylcholine.

Fill in the Blanks

What is the name of the molecule that provides the energy for the sliding process?

Multiple Select

Graded responses can be produced by changing...

• frequency of muscle contraction

• number of muscle cells being stimulated at one time

• duration of muscle contraction

Multiple Choice

Which of these is a twitch?

Multiple Choice

True or False: Muscle fiber contraction is "all of none".

• True

• False

Multiple Choice

What is the fastest way to generate ATP?

• Direct phosphorylation of ADP by Creatine Phosphate

• Anaerobic glycolysis and lactic acid formation

• Aerobic respiration

Multiple Choice

Which requires oxygen?

• Direct phosphorylation of ADP by Creatine Phosphate

• Anaerobic glycolysis and lactic acid formation

• Aerobic respiration

Multiple Select

Which of the following are causes of muscle fatigue

• ionic imbalances

• lactic acid accumulation in muscle

• decrease in ATP supply

• too much calcium

Poll

I can explain how a muscle contracts.

• 0 - Clueless

• 1 - Basic Knowledge - Need some tutoring

• 2 - Advanced Knowledge - Can apply it

• 3 - Expert - Can tutor others

Poll

I can explain how oxygen debt develops and how a muscle may become fatigued.

• 0 - Clueless

• 1 - Basic Knowledge - Need some tutoring

• 2 - Advanced Knowledge - Can apply it

• 3 - Expert - Can tutor others